This invention relates generally to the ink-jet printing art for ejecting ink droplets on a recording medium, such as paper, and more particularly, to an assembly for sealing an outlet port of an ink tank cartridge for use in an ink-jet type recording apparatus such as a printer.
In a conventional recording apparatus, ink is supplied to a recording head from an ink tank constructed as a cartridge. A benefit of using an ink cartridge serving as an ink tank is that ink does not smear due to the leakage of ink while refilling new ink or the like. However, undesired air bubbles can easily enter the ink tank during the filling process which cause problems such as ink supply failure. Controlling the leakage of ink from the cartridge is also a concern.
A cartridge is often divided into multiple chambers, where a porous foam or material is positioned over an outlet port in one chamber and free ink is filled into the other chamber. The free ink migrates from its chamber into the foam through an opening providing communication between the two chambers. The foam then controls the flow of ink as it migrates toward the ink outlet port.
When manufacturing such cartridges, the ink must be contained in the cartridge until the cartridge is mounted into the ink-jet recording device. The ink is contained within the cartridge using a sealing mechanism that is later pierced by an ink supply needle of the ink-jet recording apparatus. Prior art cartridges show sealing the outlet ports of such cartridges using a foil type structure that is pierced by the ink supply needle. Still other use a seal member such as a septum, grommet, or o-ring type seal assembly, either alone or in conjunction with the foil seal.
The sealing mechanism is exposed to pressures that tend to push or blow out these known seal members. For example, ink is pressure filled into the cartridge and the seal member must be capable of withstanding the pressure. Likewise, once the cartridge is filled, pressure differentials are exerted across the seal member and it must be securely maintained in position. Still further, the seal member is subject to manual deformation as the cartridge is inserted and removed from the supply needle associated with the printer. Again, known seal structures have attempted to minimize the impact of these forces on the seal member so that it is securely retained in place. These proposed solutions are deemed too difficult, expensive, or impractical.
Accordingly, a need exists to develop a new and improved ink cartridge having an improved seal assembly that overcomes the above stated problems and provides better, more advantageous overall results.
Generally speaking, in accordance with the invention, an ink tank cartridge is provided for an ink-jet type recording apparatus being removably mounted on an ink supply needle of a recording body.
More particularly, the invention relates to a mechanical sealing assembly for sealing an outlet port of an ink tank cartridge used with an ink-jet type recording apparatus, such as an ink-jet printer, which is removably mountable onto an ink supply needle of the recording apparatus. The ink tank cartridge includes a housing having a bottom wall and a plurality of side walls forming a cavity. The bottom wall of the housing has an opening allowing ink to pass through. An outlet port depends from the bottom wall and has a pipe-like structure or chimney that communicates with the chamber through the bottom wall opening. The chimney has spaced apart ribs extending longitudinally along its outer surface.
A sealing member is placed inside the outlet port to seal ink inside the chamber. A retaining ring or cap is attached to an outlet end of the outlet port to retain the sealing member within the port while the ink tank cartridge is subjected to pressure differentials, and selectively secured to and removed from the ink-jet type printer. The retaining cap has a central opening so that the sealing member is accessible through the opening. The ink supply needle passes through the opening in the cap to pierce the sealing member when and as the cartridge is installed in the printer. The retaining cap has a peripheral wall defining slots that can receive the outlet port ribs.
Still other aspects of the invention will become apparent to those skilled in the art upon reading and understanding the following detailed description.